I am in the "better safe than sorry" camp. I don't live down there, but if I did, I would have evacuated if it was at all possible, and I realize it isn't possible for some folks.
I do live in tornado country, and I hear lots of criticism about all the tornado warnings that turn out to be nothing. But when the sirens go off, I head to the basement, even if the sun is still shining. (Yes, I realize that is a trivial action compared to boarding every thing up and evacuating your home).